Which method of heat transfer primarily involves direct contact?

The method of heat transfer that primarily involves direct contact is conduction. In conduction, heat energy is transferred between molecules through physical contact, where faster-moving particles transfer their energy to slower-moving particles. This process occurs in solids, where the particles are closely packed, allowing for efficient transfer of heat. For example, when a metal spoon is placed in a hot pot of soup, heat is conducted through the spoon from the hotter soup to the cooler parts of the spoon via direct molecular contact.

In contrast, convection involves the movement of fluid (liquid or gas) which carries heat with it, and radiation refers to the transfer of heat through electromagnetic waves, such as infrared radiation, without the need for direct contact or a medium. Evaporation involves the transition of a substance from liquid to gas, which is related to heat transfer but not through direct contact. Thus, conduction is the correct answer as it directly describes heat transfer occurring through physical touch.